This application claims the priority of German application 196 33 948.0 filed in Germany on Aug. 22, 1996, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a selecting device for an automatic transmission of a motor vehicle of the type having a shifting channel for preselecting the individual driving positions in the automatic operation by way of a mechanical connection between the selecting device and at least one hydraulic transmission control device and having a shifting channel for the step-by-step shifting of the gears in the manual operation.
It is known to design an automatic transmission and its selecting device such that it is possible for the driver to decide by means of the selecting device whether he wants to use a step shifting operation or an automatic driving position system.
In the case of the automatic driving position system, the operating range of the automatic transmission is divided into different manually preselectable operating positions which are called driving positions. The term "driving positions" as used here comprises all operating positions of an automatic transmission, thus also the parking or neutral position. The driving positions are engaged by operating the selecting device which, by way of a mechanical connection, controls a hydraulic transmission control and parking device.
In the step shifting operation, the automatic transmission is shifted manually by the driver. By swivelling the selector lever from a center position he can shift one gear up or back depending on the direction into which he moves the selector lever. After each shifting operation, the selector lever returns to its center position.
Such a selecting device is described in German Patent Document DE 44 26 207 C1.
Since the mounting space for the selecting device in the motor vehicle is limited, the selecting device should be as compact and small as possible.
It is therefore an object of the invention to design a selecting device for an automatic transmission of a motor vehicle such that it is constructed of as few parts as possible in a compact and small manner.
According to the invention, the object is achieved by providing an arrangement having a selector lever which is pivotably supported in a longitudinal and transverse direction of the vehicle by way of a first and a second axle disposed in a vehicle-fixed frame and which, by about the first axle, can be moved in the longitudinal direction of the vehicle in one of the shifting channels respectively which extend in parallel and, by the swivelling about the second axle, can be shifted back and forth between these shifting channels in the transverse direction of the vehicle, wherein the mechanical connection is a tension/pressure connection which transmits longitudinal movements and which, in the automatic operation, is linked directly to the selector lever.
According to the invention, the mechanical connection between the selecting device and at least the hydraulic transmission control device is a tension/pressure connection which transmits longitudinal movements and which, in the case of an automatic operation in the driving position selection channel, is linked directly to the selector lever.
This has the advantage that the operating lever is eliminated to which, according to the state of the art, the tension/pressure connection is mounted which is constructed as a selecting cable. Also, because of the elimination of the operating lever, the additional components of the selecting device can be arranged in an even more space-saving and compact manner. Furthermore, they can be designed and arranged even more easily for carrying out several functions.
A preferred embodiment of the invention provides that, during the step-by-step shifting of the gears in the manual operation in the step shifting channel, the tension/pressure connection is uncoupled from the selector lever. This provides a particularly simple possibility of mutually uncoupling the step shifting system and the driving position selecting device.
Additional advantageous embodiments of the invention optimize it in addition with respect to the space requirement and the number of components. Also, an even simpler construction is achieved which lowers the manufacturing and mounting costs of the selecting device and ensures its reliable operation.
If the selecting device is constructed such that the selector lever is disposed by way of the first axle on the shifting gate which is mounted by way of the second axle on the frame, during the pivoting of the selector lever from one shifting channel into the other, this shifting gate can be pivoted along with the selector lever. The detent devices for fixing the shifting channels can simply be constructed on the shifting gate and the frame fixed to the vehicle. On this frame, the stop face will then be constructed which limits the longitudinal movement of the selector lever at the point at which its transverse movement between the shifting channels can be carried out. Between the selector lever and the shifting gate and the tension/pressure connection, particularly a holding extension on the selector-lever-side end of the tension/pressure connection, various effective surfaces are advantageously arranged in a simple manner which form-lockingly engage in one another for the operation of the step shifting system or of the driving position selecting device. All locking and operating functions for the selector lever are controlled by effective surfaces on the selector lever, the frame, the shifting gate and the tension/pressure connection, which permits a very simple construction of the selecting device.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.